This project compares Family History Positive (FHP) for alcoholism subjects to matched Family History Negative (FHN) subjects derived from the project Principal Investigator's National Institute on Alcohol Abuse and Alcoholism-funded longitudinal study of drinking behavior in a 2000 college freshman population (known as the Brain and Alcohol Research in College Students study (BARCS)). The age of these subjects is a valuable one at which to capture the transition from harmful use to abuse/dependence. This project explores the effects of memantine in a double-blind, randomized, counterbalanced manner on alcoholism risk-relevant tasks. More specifically, this project studies functional MRI tasks related to different aspects of reward and/or impulsivity-related behavior in different contexts, compares the underlying neural circuitry across tasks, and uses a pharmacologic probe of the glutamatergic system to examine NMDA/DA interactions. The combined measures provide the opportunity to advance our understanding of specific aspects of brain function related to familial alcoholism vulnerability in an already well-characterized population as some members evolve into alcohol abuse. In addition to conventional within-task analyses, functional network connectivity and allied approaches will be used to examine brain networks across tasks.